Fix CLANG_BOOTSTRAP_TARGETS in Release.cmake (#106407)

# Problem

Before this patch you could not build the `stage2-LLVM` for example
because you first had to manually add it to `CLANG_BOOTSTRAP_TARGETS` in
the `Release.cmake` and also add it to
`LLVM_RELEASE_FINAL_STAGE_TARGETS` in the cmake configure run. Now you
can just use `-DLLVM_RELEASE_FINAL_STAGE_TARGETS="LLVM;clang"` on the
cmake CLI and be able to build the targets `stage2-LLVM` and
`stage2-clang` without further changes to the cache file.

# Solution

Take all `LLVM_RELEASE_FINAL_STAGE_TARGETS` elements and append them
prefixed with `stage2-` to `CLANG_BOOTSTRAP_TARGETS`. Afterwards all
duplicates are removed.

0 files changed, 0 insertions, 0 deletions